An improved immersible oxygen probe for molten metals has a gas permeable body including an immersion end and a support end adapted for being supported by a lance. An oxygen cell and a thermocouple are supported in the immersion end of the body. An unobstructed gas flow passageway is provided through the gas permeable bodies and through the probe body from the immersion end to the support/connector end whereby gases released from the molten metal and sensor body during immersion readily pass through the probe and can escape from within the probe. Thus rapid analysis of the molten metal with improved accuracy within a few seconds after immersion is achieved. The probe contains a sample mold at least partially positioned in an unconfined portion of the permeable body.